The microelectronic industry is continually striving to produce ever faster and smaller microelectronic packages for use in various electronic products, including, but not limited to, computer server products and portable products, such as portable computers, electronic tablets, cellular phones, digital cameras, and the like. As these goals are achieved, microelectronic dice become smaller, and, with higher performance, comes an ever increasing number of interconnects on the active surface of a microelectronic die with an ever decreasing pitch.
Microelectronic dice are typically mounted on microelectronic substrates for packaging purposes, wherein the microelectronic substrates typical comprise a substrate core (e.g., bismaleimide triazine resin, FR4, polyimide materials, and the like) having dielectric layers (e.g., epoxy resin, polyimide, bisbenzocyclobutene, and the like) and conductive traces (e.g., copper, aluminum, and the like) formed on a first surface thereof to form a top trace network, and having dielectric layers and conductive traces formed on an opposing second surface thereof to form a bottom trace network. To achieve electrical interconnection between the top trace network and the bottom trace network, prior to forming the top and bottom trace networks, holes are drilled through the substrate core in specific locations. These holes are plated with a conductive material layer and filled with a conductive fill material to form what is known in the art as “plated through holes”. However, as these plated through holes become smaller, it becomes more difficult to fill them with the conductive fill material. For example, air pockets or bubbles may become trapped in the holes during the filling process, known as a “plug dent” defect. Such air pockets may result in a plated through hole which does not have sufficient current carrying capacity, which may result in the failure of the microelectronic package.